Automatic identification (“Auto-ID”) technology is used to help machines identify objects and capture data automatically. One of the earliest Auto-ID technologies was the bar code, which uses an alternating series of thin and wide bands that can be digitally interpreted by an optical scanner. This technology gained widespread adoption and near-universal acceptance with the designation of the universal product code (“UPC”)—a standard governed by an industry-wide consortium called the Uniform Code Council. Formally adopted in 1973, the UPC is one of the most ubiquitous symbols present on virtually all manufactured goods today and has allowed for enormous efficiency in the tracking of goods through the manufacturing, supply, and distribution of various goods.
However, the bar code still requires manual interrogation by a human operator to scan each tagged object individually with a scanner. This is a line-of-sight process that has inherent limitations in speed and reliability. In addition, the UPC bar codes only allow for manufacturer and product type information to be encoded into the barcode, not the unique item's serial number. The bar code on one milk carton is the same as every other, making it impossible to count objects or individually check expiration dates.
Currently cartons are marked with barcode labels. These printed labels have over 40 “standard” layouts, can be mis-printed, smeared, mis-positioned and mis-labeled. In transit, these outer labels are often damaged or lost. Upon receipt, the pallets typically have to be broken-down and each case scanned into an enterprise system. Error rates at each point in the supply chain have been 4-18% thus creating a billion dollar inventory visibility problem. Only with radio frequency identification (“RFID”) does the physical layer of actual goods automatically tie into software applications, to provide accurate tracking.
The emerging RFID technology employs a radio frequency (“RF”) wireless link and ultra-small embedded computer chips, to overcome these barcode limitations. RFID technology allows physical objects to be identified and tracked via these wireless “tags”. It functions like a bar code that communicates to the reader automatically without needing manual line-of-sight scanning or singulation of the objects. RFID promises to radically transform the retail, pharmaceutical, military, and transportation industries.
The advantages of RFIDs over bar code are summarized in Table 1:
TABLE 1BarcodeRFIDNeed line-of-sight to readIdentification without visualcontactRead onlyAble to read/writeOnly a barcode numberAble to store information in tagBarcode number is fixedInformation can be renewedanytimeCategory level tagging only-noUnique item identificationunique item identifierUnable to read if barcode isCan withstand harsh environmentdamagedUse onceReusableLow costHigher costLess FlexibilityHigher Flexibility/Value
As shown in FIG. 1, an RFID system 100 includes a tag 102, a reader 104, and an optional server 106. The tag 102 includes an IC chip and an antenna. The IC chip includes a digital decoder needed to execute the computer commands the tag 102 receives from the tag reader 104. The IC chip also includes a power supply circuit to extract and regulate power from the RF reader; a detector to decode signals from the reader; a transmitter to send data back to the reader; anti-collision protocol circuits; and at least enough EEPROM memory to store its EPC code.
Communication begins with a reader 104 sending out signals to find the tag 102. When the radio wave hits the tag 102 and the tag 102 recognizes the reader's signal, the reader 104 decodes the data programmed into the tag 102. The information is then passed to a server 106 for processing. By tagging a variety of items, information about the nature and location of goods can be known instantly and automatically.
The system uses reflected or “backscattered” radio frequency (RF) waves to transmit information from the tag 102 to the reader 104. Since passive (Class-1 and Class-2) tags get all of their power from the reader signal, the tags are only powered when in the beam of the reader 104.
The Auto ID Center EPC-Compliant tag classes are set forth below:
Class-1                Identity tags (RF user programmable, maximum range 3 m)        Lowest cost (AIDC Targets: 5¢ moving down to 2¢ in trillion-unit/yr volumes)        
Class-2                Memory tags (8 bits to 128 Mbits programmable at maximum 3 m range)        Security & privacy protection        Low cost (AIDC Targets: typically 10¢ at billion-unit volumes)        
Class-3                Battery tags (256 bits to 64 Kb)        Self-Powered Backscatter (internal clock, sensor interface support)        100 meter range        Moderate cost (Targets: $50 currently, $5 in 2 years, 20¢ at billion-unit volumes)        
Class-4                Active tags        Active transmission (permits tag-speaks-first operating modes)        Up to 30,000 meter range        Higher cost (Targets: $10 in 2 years, 30¢ in billion-unit volumes)        
Semi-passive and active tags have a battery to provide power to the chip. This greatly increases read range, and the reliability of tag reads, because the tag doesn't need power from the reader. Class-3 tags only need a 10 mV signal from the reader in comparison to the 500 mV that a Class-1 tag needs to operate. This 2,500:1 reduction in power requirement permits Class-3 tags to operate out to a distance of 100 meters or more compared with a Class-1 range of only about 3 meters.
In a retail environment, RFID tags can be affixed to goods, each tag having a unique identifier (ID) that identifies the tag, a password that ensures that only the retailer system can communicate with the tag, and a kill password that disables the tag. Then, instead of requiring a cashier to scan the UPC bar code for each item, an RFID reader can simply scan the tags attached to all of the items in the customer's cart almost instantaneously. The kill passwords can then be used to disable the tags. Particularly, because each item has a tag that uniquely identifies that individual item, the retailer computer system can quickly determine the price of the item, remove that item from present inventory, disable the tag to protect the privacy of the consumer, etc. The benefits of such an RFID system are evident.
Current distribution systems require the distributor to parallel the physical delivery of goods with electronic delivery of the passwords for tags affixed to the goods. A problem arises, however, due to the fact that the tags and passwords are not delivered together. The physical goods pass through a whole series of warehouses and trucks prior to reaching their final destination. Goods from varying sources are often consolidated in trucks and reach the store together. However, the passwords go to servers all throughout the Internet, with no relationship to the physical transfer of the goods whatsoever.
The passwords from the many different manufacturers must ultimately be aggregated locally in order to be able to sell the items. However, the huge number of tags present at any one establishment coupled with the inherent difficulties in keeping track of every single tag received at the store and its corresponding, electronically-delivered passwords creates an almost insurmountable barrier to efficient operations. The task is compounded even further by the inevitable misdelivery or rerouting of goods.
A further problem is that electronic delivery of tag passwords is not 100% secure, as the passwords must be downloaded via the Internet, received in an email, etc. A hacker or eavesdropper could potentially intercept the transmission and obtain the passwords. With the passwords, a hacker could potentially disable tags and steal items, and even mischievously disable entire sets of tags in the store, opening the door to theft.
Another problem with electronic delivery of passwords is the time required. When the goods arrive at the store, their tags need to be accessed. However, if the tags are cloaked, their passwords must be sent to them before they will disclose their data. If the passwords are not readily available, the RFID system must retrieve them from a remote network site before they can be moved onto shelves.
Further, some systems attempt to download the passwords on an as-needed basis. However, this causes delays, as the RFID system may need to search up through several layers of software to find the correct password list, find the correct password, verify that the RFID system is authorized to download the password, download the password, and then only perform the read. Thus, several seconds can elapse for each item, meaning that the pallet will have to remain in the scan area until each item therein is identified.
Another issue is personal privacy. Assuming a retailer cannot retrieve the passwords and uses UPC codes instead, the tags remain active. If the retailer does not have kill passwords, it cannot disable the tags at checkout. If the tags remain live, a rogue reader can query the tags to determine what a customer has purchased. This raises privacy concerns, particularly where sensitive items such as prescriptions are being purchased.
What is needed is a way to store passwords and other information for a first device in a second device that is secure and readily available to the system which will ultimately require the information.
What is also needed is a way to take advantage of the physical transfer of goods throughout a supply chain to also deliver electronic data about those goods and tags coupled thereto.